Respiratory interface devices are used for various reasons. Typically a respiratory interface device includes a mask portion interconnected with a source of breathable fluid to be inhaled by a patient. Examples of uses of these devices include the delivery of anesthesia, non-invasive ventilation, and for providing positive air pressure to a patient in the treatment of obstructive sleep apnea. In the treatment of obstructive sleep apnea, positive air pressure is provided to a patient while the patient is sleeping.
Accordingly, in uses such as the treatment of obstructive sleep apnea, mask comfort is important to ensure that the patient may sleep and also to ensure that the patient complies with the treatment. For the treatment of obstructive sleep apnea, the mask must provide a sufficient seal to enable pressure to be maintained within the airway of the patient.
Typical respiratory interface devices are bulbous and enclose a large portion of the nose and engage the face of the patient. Additionally, such devices are typically secured to a patient's head via the use of multiple straps and other apparatus. It is common for such devices to include a forehead support and related straps to counteract the forces exerted on the device by the conduit or other member supplying the breathable fluid to the mask and thus maintain proper alignment of the mask. These devices tend to be cumbersome to position and secure on a patient's head and also produce a claustrophobic effect on the patient. Examples of such devices and related headgear can be found in U.S. Pat. Nos. 5,517,986; 6,119,694, and 7,069,932.